Centos MySQL8 configuration

change Password##

1. View initial password

grep 'temporary password'/var/log/mysqld.log

2. Connect to MySQL, enter the following code, press Enter and enter the above password

mysql -uroot -p

3. Select database

use mysql;

4. Leave authentication_string blank

update user set authentication_string='' where user='root';

Note: In mysql8.0 and above,

update mysql.user set password='newpassword' where user='root';
 
update mysql.user set password=PASSWORD('newpassword') where User='root';

These two commands no longer work

5. change Password

ALTER USER 'root'@'localhost' IDENTIFIED BY 'new password';

There will be an error as follows:
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements

This is actually related to the value of validate_password_policy

The following values are available:

The default is 1, which is MEDIUM, so the password set at the beginning must meet the length, and must contain numbers, lowercase or uppercase letters, and special characters.
Sometimes, I just want to test myself and don’t want the password to be so complicated. For example, I just want to set the root password to 123123.

This is the time, Wimbledon can modify a few global variables when using it to enter the database for the first time, or skip the permission table to enter the database again!

mysql> show variables like "%validate%";+--------------------------------------+--------+| Variable_name                        | Value  |+--------------------------------------+--------+| query_cache_wlock_invalidate         | OFF    || validate_password_check_user_name    | OFF    || validate_password_dictionary_file    ||| validate_password_length             |8|   ##The minimum length of the password, change to 6| validate_password_mixed_case_count   |1|| validate_password_number_count       |1|| validate_password_policy             | MEDIUM |   #Change this to 0, you can accept a simple password
| validate_password_special_char_count |1|+--------------------------------------+--------+
# Modify global variables
mysql>set global validate_password_length=6;
Query OK,0 rows affected(0.00 sec)

mysql>set global  validate_password_policy=0;
Query OK,0 rows affected(0.00 sec)

mysql> show variables like "%validate%";+--------------------------------------+-------+| Variable_name                        | Value |+--------------------------------------+-------+| query_cache_wlock_invalidate         | OFF   || validate_password_check_user_name    | OFF   || validate_password_dictionary_file    ||| validate_password_length             |6|| validate_password_mixed_case_count   |1|| validate_password_number_count       |1|| validate_password_policy             | LOW   || validate_password_special_char_count |1|+--------------------------------------+-------+8 rows inset(0.00 sec)

mysql> alter user 'root'@'localhost' identified by '123123';  #Change the password again, there will be no more mistakes!
Query OK,0 rows affected(0.01 sec)

from:

https://blog.csdn.net/ssiyla/article/details/82931439

https://www.cnblogs.com/mzxiaoze/p/10413399.html